How Does St. John's Wort Work?

General Overview

St. John's wort (Latin name: Hypericum perforatum) is a yellow flower plant that blooms in late June. It's widely known as a medicinal herb that has been used for a variety of illnesses since ancient times. Throughout history, St. John's wort has been used to treat mental illnesses, nervous system disorders, burns, and minor wounds. The flowering tops and petals of the herb are made into tablets, capsules, powders, and teas. They are sold in pharmacies and health stores. Currently, the herb is used to treat mild to moderate depression, anxiety and insomnia.

How It Works

Two major scientific studies on the efficacy of St. John's wort have found that it is helpful in treating mild to moderate depression and anxiety. However, the herb has proved ineffective in treating major depression. The active component in St. John's wort is hypericin, which is found in the leaves and flowers of the plant. When it comes to milder forms of depression, St. John's wort works similarly to traditional depression and anxiety medications in the SSRI (selective serotonin reuptake inhibitors) class such as sertraline. It basically works by inhibiting serotonin reuptake, which is largely thought to cause neurological disorders. Additionally, due to its anti-inflammatory properties, the herb is used to treat minor burns and cuts.

Side Effects and Interactions

Due to its powerful use as a medicinal treatment for a variety of disorders, St. John's wort has the potential to cause several side effects and adverse interactions when used in conjunction with other medications. Side effects include dizziness, skin rash, headache, dry mouth, upset stomach, fatigue and restlessness. St. John's wort should always be used under the guidance of a physician especially if it is taken with other medication. The herb reacts with several different types of medication causing them to lose their efficacy. St. John's wort should not be taken with antidepressant medications, immunosuppressive medications, HIV medications, oral contraceptives, digoxin, theophylline, warfarin, loperamide, and reserpine. St. John's wort should also not be used by women who are pregnant or may become pregnant.

Resources

• Scientific studies on St. John's wort